The White Sox announced that they have signed lefty reliever Aaron Bummer to a five-year extension worth $16 million. The deal also includes two club options that could bring Bummer’s total earnings up to $30.75 million. Both options include buyouts for $1.25 million, meaning Bummer is guaranteed at least $17.25 million. Bob Nightengale notes that this is the largest contract extension for a pre-arb non-closer in history.

Bummer wasn’t scheduled to be arbitration-eligible until next offseason, but the White Sox were clearly impressed enough by Bummer’s breakout 2019 to lock him up with a cost-controlled deal right now. After a relatively nondescript first two seasons in the majors, Bummer emerged as a force in the back end of the Chicago bullpen last year. He worked to a 2.13 ERA over 67.2 innings, bolstered by a ridiculous 72.1% ground ball rate. Only Zack Britton induced more grounders. Bummer also boasted a sub-1 WHIP. Baseball Prospectus’ DRA metric graded Bummer out at a 2.99. He’s for real.

Bummer is just 26, and he’s going to have a talented middle infield tandem of Tim Anderson and Nick Madrigal working behind him for a long time to come. This is a great move by the White Sox, and it’s cool to see a team value a pre-arb reliever with just one career save this highly.

Their bullpen isn’t too sexy besides Bummer, with Alex Colomé and Steve Cishek being the main attractions. This is still an area that GM Rick Hahn will need to build on if the Sox want to be true contenders. Getting Bummer to sign a long-term deal is a great first step.